Power supply unit for aerosol generation device

ABSTRACT

A power supply unit for an aerosol generation device is provided. The power supply unit includes an internal power supply configured to hold power supplied to a heater configured to heat an aerosol source, a connector connectable to an external power supply, a controller configured to control power supply from the internal power supply to the heater, and a first transistor positioned on a first power supply path between the connector and a positive electrode of the internal power supply. A current from the connector is supplied to a source of the first transistor. A current from a drain of the first transistor is supplied to the positive electrode of the internal power supply. The controller controls a voltage of a gate of the first transistor to adjust power supplied from the external power supply to the internal power supply.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention contains subject matter related to Japanese PatentApplication No. 2020-150105 filed in the Japan Patent Office on Sep. 7,2020, the entire contents of which are incorporated herein by reference.This application is also related to U.S. Ser. No. 17/464,724, entitled:“POWER SUPPLY UNIT FOR AEROSOL GENERATION DEVICE” and U.S. Ser. No.17/464,707, entitled: “POWER SUPPLY UNIT FOR AEROSOL GENERATION DEVICE”filed on the same day as this application and hereby incorporated byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a power supply unit for an aerosolgeneration device.

Description of the Related Art

An aerosol generation device such as an electronic cigarette includes aninternal power supply such as a battery, and power is supplied from thisinternal power supply to a heater. The aerosol generation device isconnected to an external power supply to charge the internal powersupply. In WO 2019/150546, a controller uses a charging integratedcircuit different from a controller to control power supplied from theexternal power supply to the internal power supply. When the chargingintegrated circuit for controlling the power supplied from the externalpower supply to the internal power supply is used, a circuit scaleincreases.

SUMMARY OF THE INVENTION

An aspect of the present disclosure provides a technique of reducing thecircuit scale of a power supply unit of an aerosol generation device.

According to an embodiment, a power supply unit for an aerosolgeneration device is provided. The power supply unit includes aninternal power supply configured to hold power supplied to a heaterconfigured to heat an aerosol source, a connector connectable to anexternal power supply, a controller configured to control power supplyfrom the internal power supply to the heater, a first transistor of adropper type positioned on a first power supply path between theconnector and a positive electrode of the internal power supply, acircuit board mounted with the controller and including ground, and acurrent detection circuit configured to detect at least one of a firstcurrent flowing from a negative electrode of the internal power supplyat the time of charging the internal power supply and a second currentflowing into the negative electrode of the internal power supply at thetime of discharging from the internal power supply. A current from theconnector is supplied to a source of the first transistor, and a currentfrom a drain of the first transistor is supplied to the positiveelectrode of the internal power supply. The controller performs feedbackcontrol on a voltage of a gate of the first transistor based on acurrent or a voltage supplied from the first transistor, therebyadjusting power supplied from the external power supply to the internalpower supply. The negative electrode of the internal power supply is notconnected to the ground of the power supply unit.

According to another embodiment, a power supply unit for an aerosolgeneration device is provided. The power supply unit includes aninternal power supply configured to hold power supplied to a heaterconfigured to heat an aerosol source, a connector connectable to anexternal power supply, a controller configured to control power supplyfrom the internal power supply to the heater, a first transistor of adropper type positioned on a first power supply path between theconnector and a positive electrode of the internal power supply, and aSchottky diode. A current from the connector is supplied to a source ofthe first transistor, and a current from a drain of the first transistoris supplied to the positive electrode of the internal power supply. Thecontroller performs feedback control on a voltage of a gate of the firsttransistor based on a current or a voltage supplied from the firsttransistor, thereby adjusting power supplied from the external powersupply to the internal power supply. An anode of the Schottky diode isconnected to the drain of the first transistor, and a cathode of theSchottky diode is connected to the source of the first transistor.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view for explaining an example of the arrangement of anaerosol generation device according to an embodiment of the presentdisclosure;

FIG. 2 is a diagram for explaining an example of the circuit arrangementof a power supply unit according to the embodiment of the presentdisclosure;

FIG. 3 is a diagram for explaining a current when the internal powersupply of the embodiment of the present disclosure is charged;

FIG. 4 is a diagram for explaining a current when the internal powersupply of the embodiment of the present disclosure is discharged; and

FIGS. 5A and 5B are diagrams for explaining the connector and polarityunification circuit of the embodiment of the present disclosure indetail.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference tothe accompanying drawings. It should be noted that the followingembodiments are not intended to limit the scope of the appended claims,and that not all the combinations of features described in theembodiments are necessarily essential to the present invention. Of aplurality of features described in the embodiments, two or more featuresmay arbitrarily be combined. In addition, the same reference numeralsdenote the same or similar parts, and a repetitive description will beomitted.

FIG. 1 schematically shows the arrangement of an aerosol generationdevice 100 according to an embodiment. The aerosol generation device 100can be configured to provide, to a user via an inhalation port 130, agas containing an aerosol, a gas containing an aerosol and a flavormaterial, an aerosol, or an aerosol containing a flavor material inaccordance with an operation requesting the aerosol (to be also referredto as an aerosol requesting operation hereinafter) such as an inhalationoperation by the user. The aerosol generation device 100 can comprise apower supply unit 102 and an atomizer 104. The aerosol generation device100 can comprise a holding portion 103 that detachably holds theatomizer 104. The power supply unit 102 may be understood as aninhalation unit controller. The atomizer 104 can be configured toatomize an aerosol source. The aerosol source, can be, for example, aliquid such as a multivalent alcohol such as glycerin or propyleneglycol. Alternatively, the aerosol source may contain a drug. Theaerosol source can be a liquid, a solid, or a mixture of a liquid and asolid. A vapor source such as water may be used in place of the aerosolsource.

The aerosol generation device 100 may further comprise a capsule 106containing a flavor source 131. The atomizer 104 can include a capsuleholder 105 that detachably holds the capsule 106. The flavor source 131can be a molded body obtained by molding, for example, a cigarettematerial. Alternatively, the flavor source 131 may be made of a plant(for example, mint, herb, Chinese medicine, coffee beans, or the like)except the cigarette. A fragrance such as menthol may be added to theflavor source. The flavor source 131 may be added to an aerosol source.Note that the capsule holder 105 may be arranged in the power supplyunit 102 in place of the atomizer 104. The atomizer 104 and the capsuleholder 105 may be integrally formed in place of an arrangement in whichthe aerosol generation device 100 or the atomizer 104 includes thecapsule holder 105.

The power supply unit 102 can include electrical components 110. Theelectrical components 110 can include a user interface 116.Alternatively, the power supply unit 102 may be understood to includethe electrical components 110 and the user interface 116. The userinterface 116 can include a display unit DISP (for example, a lightemitting element such as an LED (Light Emitting Diode) and/or an imagedisplay unit such as an LCD) and/or an operation unit OP (for example, aswitch such as a button switch and/or a touch display).

The holding portion 103 of the power supply unit 102 can include anelectrical contact C1 and an electrical contact C2. In a state in whichthe atomizer 104 is held by the holding portion 103, the electricalcontact C1 of the holding portion 103 can contact an electrical contactC3 of the atomizer 104, and the electrical contact C2 of the holdingportion 103 can contact an electrical contact C4 of the atomizer 104.The power supply unit 102 can supply power to the atomizer 104 via theelectrical contact C1 and the electrical contact C2.

The atomizer 104 can include the electrical contact C3 and theelectrical contact C4 described above. In addition, the atomizer 104 caninclude a heater HT for heating the aerosol source, a container 125 forholding the liquid aerosol source, and a transport portion 126 fortransporting the aerosol source held by the container 125 to a heatingregion of the heater HT and holding the aerosol source in the heatingregion. The transport portion 126 is called a wick. At least part of theheating region of the heater HT can be arranged in a channel 128 formedin the atomizer 104. The electrical contact C1, the electrical contactC3, the heater HT, the electrical contact C4, and the electrical contactC2 form a current path for flowing the current to the heater HT. Thetransport portion 126 can be made of a fiber element such as a glassfiber, a porous material such as a ceramic, or a combination thereof.Note that the unit for transporting the aerosol source held in thecontainer 125 to the heating region is not limited to the wick, but aspraying device such as a spray or a transporting unit such as a pumpmay be used instead.

As described above, the atomizer 104 can include the capsule holder 105for detachably holding the capsule 106. As an example, the capsuleholder 105 can hold the capsule 106 such that part of the capsule 106 isaccommodated in the capsule holder 105 or the atomizer 104 and theremaining part of the capsule 106 is exposed. The user can hold theinhalation port 130 with his/her mouth and suck the gas containing theaerosol. Since the detachable capsule 106 includes the inhalation port130, the aerosol generation device 100 can be kept clean.

When the user holds the inhalation port 130 with his/her mouth andperforms the inhalation operation, as exemplified by an arrow, air flowsinto the channel 128 of the atomizer 104. When the heater HT heats theaerosol source, the vaporized and/or aerosolized aerosol source istransported toward the inhalation port 130 with the air. In the processin which the aerosol source is transported toward the inhalation port130, the vaporized and/or aerosolized aerosol source is cooled to formfine liquid droplets, thereby promoting aerosolization. In thearrangement in which the flavor source 131 is arranged, the flavormaterial generated by the flavor source 131 is added to this aerosol,and the resultant material is transported to the inhalation port 130,thus allowing the user to suck the aerosol containing the flavormaterial. Since the flavor material generated by the flavor source 131is added to the aerosol, the flavor material can be efficientlytransported to the lungs of the user without staying in the oral cavity.

The power supply unit 102 further includes a connector PG connected toan external device (not shown in FIG. 1). The external device connectedto the power supply unit 102 can be, for example, a charger of the powersupply unit 102. In this case, the external device functions as anexternal power supply for supplying power to the power supply unit 102.The external device may communicate with the power supply unit 102 viathe connector PG.

In the example shown in FIG. 1, the atomizer 104 detachable from thepower supply unit 102 includes the heater HT. The heater HT may beattached to the power supply unit 102 in place of the atomizer 104. Inthis case, an aerosol generation product including an aerosol base thatholds the aerosol source and a filter may be exchangeably attached tothe power supply unit 102. The aerosol generation product is insertedinto the heater HT of the power supply unit 102, and accordingly theheater HT can heat the aerosol source in the aerosol base. The usedaerosol generation product can be detachable from the power supply unit102 in a state in which the heater HT is coupled to the power supplyunit 102.

FIG. 2 shows an example of the overall circuit arrangement of the powersupply unit 102. In some embodiments, the power supply unit 102 includesa plurality of circuit components shown in FIG. 2. The outline of thearrangement of each circuit component will be described with referenceto FIG. 2, and then details of some circuit components will be describedlater with reference to other drawings.

A controller 14 controls the overall operation of the power supply unit102. The controller 14 can be a microcontroller unit formed by, forexample, an integrated circuit (IC). More specifically, the controller14 supplies a control signal to each circuit component in the powersupply unit 102 to control the operation of each circuit component. Inaddition, the controller 14 controls power supply from an internal powersupply BAT to the heater HT.

The internal power supply BAT is a power supply for holding powersupplied to the heater HT in order to heat the aerosol source. Theinternal power supply BAT can be formed by a primary battery such as adry cell, a secondary battery such as a lithium ion battery, or acapacitor such as an electric double layer capacitor. In the followingdescription, a case in which the internal power supply BAT is formed bythe secondary battery will be described, unless otherwise specified.

A connector 23 is a connector connectable to an external device CG. Theexternal device CG includes a connector 24. When the connector 23 of thepower supply unit 102 is physically connected (coupled) to the connector24 of the external device CG, the power supply unit 102 and the externaldevice CG are electrically connected to each other. The connector 23 andthe connector 24 can be connectable in a plurality of differentdirections.

The external device CG can supply power to the internal power supply BATvia the connectors 23 and 24. In addition, the external device CG cancommunicate with each circuit component in the power supply unit 102. Inthe example shown in FIG. 2, the external device CG and the power supplyunit 102 perform I2C (Inter-Integrated Circuit) communication as a typeof serial communication method. Each circuit component which performscommunication in the power supply unit 102 includes a communicationterminal (“SCL” in FIG. 2) for transmitting/receiving a clock signal anda communication terminal (“SDA” in FIG. 2) for transmitting/receiving adata signal. The clock signal communication terminals of the respectivecircuit components are connected to each other, and the data signalcommunication terminals of the respective circuit components areconnected to each other. In the example shown in FIG. 2, I2Ccommunication is performed. However, another serial communication methodsuch as UART (Universal Asynchronous Receiver/Transmitter) or SPI(Serial Peripheral Interface) may be used in place of the I2Ccommunication. The external device CG can transmit data to the writeterminal (“WRT” in FIG. 2) of the controller 14.

If the internal power supply BAT is formed by the primary battery, theexternal device CG need not have a charging function, but can have onlya communication function. Alternatively, the external device CG need nothave the communication function, but may have only the chargingfunction, or may have both the communication function and the chargingfunction. If the external device CG has the charging function, theexternal device CG can be referred to as the external power supply. Inthe following description, a case in which the external device CG hasboth the charging function and the communication function will bedescribed, unless otherwise specified.

A polarity unification circuit BC is a circuit component for unifyingthe polarity of the connector 23. The polarity unification circuit BC isconnected to the two power supply terminals of the connector 23. Of thepotentials supplied to the two power supply terminals of the connector23, the polarity unification circuit BC connects a higher potential (forexample, a power supply potential VBUS of the external device CG) to thepositive electrode (via another electrical component) of the internalpower supply BAT and a lower potential (for example, the groundpotential of the external device CG) to the negative electrode (viaanother electrical component) of the internal power supply BAT. A fuseFS is arranged between the polarity unification circuit BC and theconnector 23. If a current flowing between the polarity unificationcircuit BC and the connector 23 exceeds a threshold, the fuse FS isdisconnected. Accordingly, power supply from the external device CG tothe power supply unit 102 is stopped.

A protection IC 16 is a circuit component for protecting the circuitcomponents in the power supply unit 102 from an excessive current. Theprotection IC 16 is positioned on the power supply path for supplyingpower from the external device CG to the internal power supply BAT. If acurrent flowing through the protection IC 16 exceeds the threshold for apredetermined period, the protection IC 16 sets, to the disconnectedstate, the power supply path through which the current flows through theprotection IC 16. Accordingly, the power supply from the external deviceCG to the power supply unit 102 is stopped to protect a subsequentcircuit (for example, a transistor Q3). The protection IC 16 isconnected to a ground line GL of the power supply unit 102. The groundline GL is connected to ground of a circuit board on which each circuitcomponent (for example, the controller 14) of the power supply unit 102is mounted. As a detailed example, ground of the circuit board is madeof a metal plate.

A transistor Q4 is a circuit component for preventing the flow of acurrent to the connector 23 during the power supply from the internalpower supply BAT to the heater HT. The transistor Q4 can be an FET(Field Effect Transistor) or an IGBT (Insulated Gate type BipolarTransistor). The transistor Q4 may be an n-channel MOS transistor. Thisalso applies to other transistors to be described later. The transistorQ4 is positioned on the power supply path for supplying power from theexternal device CG to the internal power supply BAT. The transistor Q4is arranged such that the direction from the external device CG to theinternal power supply BAT is the forward direction of a parasitic diodeof the transistor Q4. The gate of the transistor Q4 is connected to thecontroller 14.

The transistor Q3 is a circuit component for adjusting the amount ofpower supplied from the external device CG to the internal power supplyBAT. The protection IC 16 is positioned on the power supply path forsupplying power from the external device CG to the internal power supplyBAT. The transistor Q3 is positioned such that the direction from theexternal device CG to the internal power supply BAT is the reversedirection of the parasitic diode of the transistor Q3. The gate of thetransistor Q3 is connected to the controller 14. A Schottky diode SD isconnected parallel to the transistor Q3. More specifically, the cathodeof the Schottky diode SD is connected to the source of the transistorQ3, and the anode of the Schottky diode SD is connected to the drain ofthe transistor Q3.

A protection IC 17 is a circuit component for protecting the internalpower supply BAT from the excessive current. More specifically, theprotection IC 17 measures a voltage across a resistor RP connected tothe negative electrode of the internal power supply BAT and determines acurrent flowing through the resistor RP. If this current exceeds athreshold, the protection IC 17 operates a transistor pair SP to stopthe current flowing out from the negative electrode of the internalpower supply BAT or the current flowing in the negative electrode.

A voltage converter 13 is a circuit component for converting the powersupply voltage supplied from the internal power supply BAT into a heaterdriving voltage. The power supply voltage from the internal power supplyBAT is supplied to the input terminal (“VIN” in FIG. 2) of the voltageconverter 13, and the heater driving voltage is output from the outputterminal (“VOUT” in FIG. 2) of the voltage converter 13. An enablesignal is supplied from the enable terminal (“EN” in FIG. 2) of thevoltage converter 13 to the control terminal (“EN2” in FIG. 2) of thecontroller 14. The ground terminal (“GND” in FIG. 2) of the voltageconverter 13 is connected to the ground line GL. The voltage converter13 can communicate with the controller 14 by the I2C communication. Thevoltage converter 13 may be formed by a DC/DC converter. The voltageconverter 13 may be formed by a buck-boost DC/DC converter.

The output terminal of the voltage converter 13 is connected to theheater HT via a transistor Q1. The gate of the transistor Q1 isconnected to the controller 14. The controller 14 switches the level ofthe control signal supplied to the gate of the transistor Q1 to switchON/OFF state of the transistor Q1. During the ON period of thetransistor Q1, the heater driving voltage is applied to the heater HT toheat the heater HT.

A regulator 12 is a circuit component for converting the power supplyvoltage supplied from the internal power supply BAT into a power supplyvoltage of an operational amplifier 15. The power supply voltage of theoperational amplifier 15 is used also to measure the resistance value ofthe heater HT. The regulator 12 can be a linear regulator, and morespecifically a low dropout (LDO) regulator. The power supply voltage issupplied from the internal power supply BAT to the input terminal (“IN”in FIG. 2) of the regulator 12. The power supply voltage of theoperational amplifier 15 is output from the output terminal (“OUT” inFIG. 2) of the regulator 12. An enable signal is supplied from thecontrol terminal (“EN2” in FIG. 2) of the controller 14 to the enableterminal (“EN” in FIG. 2) of the regulator 12. The ground terminal(“GND” in FIG. 2) of the regulator 12 is connected to the ground lineGL. In this embodiment, the enable terminal of the voltage converter 13and the enable terminal of the regulator 12 are connected to the commoncontrol terminal (“EN2” in FIG. 2) of the controller 14. Alternatively,the controller 14 may have individual control terminals respectivelyconnected to the enable terminal of the voltage converter 13 and theenable terminal of the regulator 12. The voltage output from the outputterminal of the regulator 12 may be kept constant.

The output terminal of the regulator 12 is connected to the heater HTvia a diode BE, a transistor Q2, and a resistor Rs. The diode BEprevents the reverse flow of the current from the transistor Q2 to theregulator 12. The gate of the transistor Q2 is connected to thecontroller 14. The controller 14 switches the level of the controlsignal supplied to the gate of the transistor Q2 to switch the ON/OFFstate of the transistor Q2. During the ON period of the transistor Q2,the output voltage of the regulator 12 is applied to the heater HT. Thenode between the transistor Q2 and the resistor Rs is connected to theground line GL via the resistor R2 and the resistor R1. The controller14 is connected to the node between the resistor R2 and the resistor R1.

The noninverting input terminal of the operational amplifier 15 isconnected to one terminal of the heater HT. The inverting input terminalof the operational amplifier 15 is connected to the other terminal ofthe heater HT. The output terminal of the operational amplifier 15 isconnected to the controller 14. The operational amplifier 15 suppliesthe voltage applied to the heater HT to the controller 14. If the heaterHT has a positive or negative temperature coefficient characteristic bywhich the resistance value changes depending on the temperature of theheater HT, the voltage applied to the heater HT has a strong correlationwith the temperature of the heater HT. The controller 14 estimates thetemperature of the heater HT based on this voltage, adjusts the amountof power supplied to the heater HT based on this estimated temperature,and controls the temperature of the heater HT based on the adjustedamount of power. In this embodiment, a voltage obtained by dividing apredetermined voltage output from the regulator 12 by the resistor Rsand the heater HT is input to the noninverting input terminal of theoperational amplifier 15. Since this divided voltage has a strongcorrelation with the temperature of the heater HT, the controller 14 canaccurately estimate the temperature of the heater HT from the voltage(the signal) output from the output terminal of the operationalamplifier 15.

A regulator 11 is a circuit component for converting the voltagesupplied from the external device CG or the internal power supply BATinto power supply voltages of a switch unit 20, a puff sensor 21, and atouch sensor 22. The voltage output from the regulator 11 is also usedas the power supply voltage of the I2C communication. The regulator 11can be a linear regulator. The power supply voltage is supplied from theexternal device CG or the internal power supply BAT to the inputterminal of the regulator 11, and the power supply voltage of eachcircuit component is output from the output terminal of the regulator11. In this embodiment, the power supply voltages of an LED driver 18and an LED 19 are not supplied from the output terminal of the regulator11, as will be described later. Alternatively, the power supply voltagesof the LED driver 18 and the LED 19 may be supplied from the outputterminal of the regulator 11. An enable signal is supplied from thecontrol terminal (“EN1” in FIG. 2) of the controller 14 to the enableterminal of the regulator 11. The ground terminal of the regulator 11 isconnected to the ground line GL. The regulator 11 can be used in both acase in which the power is supplied from the external device CG and acase in which the internal power supply BAT is discharged. On the otherhand, during the supply of power from the external device CG, theregulator 12 is not used. During the discharge of the internal powersupply BAT (more specifically, during the inhalation operation of theuser), the regulator 12 is used. For this reason, the regulator 11 canbe a power-saving component as compared with the regulator 12. Theregulator 12 generates the operation voltage of the operationalamplifier 15. The operation voltage of the operational amplifier 15influences the accuracy and speed of temperature estimation of theheater HT by the controller 14. For this reason, the regulator 12 can bea component having responsiveness higher than that of the regulator 11.

The LED driver 18 is a circuit component for controlling the operationof the LED 19. The LED 19 is equivalent to a display unit DISP inFIG. 1. The power supply voltage is supplied from the external device CGor the internal power supply BAT to the power supply terminal of the LEDdriver 18. The ground terminal of the LED driver 18 is connected to theground line GL. The LED driver 18 can communicate with the controller 14by the I2C communication. The LED driver 18 changes the ON state of theLED 19 to notify the user of the state of the aerosol generation device100. More specifically, the LED driver 18 changes the state of the LED19 as the ON state, the OFF state, or the flickering state. If the LED19 includes a plurality of LEDs, the number of ON LEDs can beincreased/decreased.

The switch unit 20 is a circuit component for changing the state of thecommunication path of the I2C communication between the connector 23 andthe controller 14 to the disconnected state or the conductive state. Thepower supply voltage is supplied from the regulator 11 to the powersupply terminal of the switch unit 20. The ground terminal of the switchunit 20 is connected to the ground line GL. The enable terminal (“EN” inFIG. 2) of the switch unit 20 is connected to the node between aresistor R4 and a resistor R3. The resistor R4 and the resistor R3 areconnected in series with each other between the line for receiving thepower supply voltage from the external device CG and the ground line GL.For this reason, the node between the resistor R4 and the resistor R3 isset at high level while the power supply voltage is supplied from theexternal device CG. This node is also connected to the detectionterminal (“VBUS” in FIG. 2) of the controller 14. When the potential ofthe detection terminal is measured, the controller 14 can detect thatthe fact that the power supply voltage is supplied from the externaldevice CG. If the voltage applied to the enable terminal is set at highlevel, the switch unit 20 sets the communication path of the I2Ccommunication between the connector 23 and the controller 14 to theconductive state. On the other hand, if the voltage applied to theenable terminal is set at low level, the switch unit 20 sets thecommunication path of the I2C communication between the connector 23 andthe controller 14 to the disconnected state. Accordingly, even if staticelectricity is applied to the communication terminal of the connector 23or the communication terminal is short-circuited, an unexpected currentwill not flow to the circuit component in the power supply unit 102.Therefore, the safety of the power supply unit 102 can be improved.

The puff sensor 21 is a circuit component for detecting the inhalationoperation of the user. As a detailed example, the puff sensor 21 isformed by a microphone condenser, a flow rate sensor, or one or morepressure sensors. The power supply voltage is supplied from theregulator 11 to the power supply terminal of the puff sensor 21. Theground terminal of the puff sensor 21 is connected to the ground lineGL. The puff sensor 21 can communicate with the controller 14 by the I2Ccommunication.

The touch sensor 22 is a circuit component for detecting the touchoperation by the user. The power supply voltage is supplied from theregulator 11 to the power supply terminal of the touch sensor 22. Theground terminal of the touch sensor 22 is connected to the ground lineGL. The touch sensor 22 notifies the controller 14 of the detectionresult of the touch operation.

A temperature sensor TM is a circuit component for measuring thetemperature near the internal power supply BAT. The temperature sensorTM can be formed by a thermistor, a thermocouple, a temperaturemeasurement resistor band, or an IC temperature sensor. For example, thecontroller 14 applies a voltage from the output terminal (“VO” in FIG.2) to the temperature sensor TM. This voltage is divided by the resistorR5 and the temperature sensor TM and input to the input terminal (“VI”in FIG. 2) of the controller 14. The controller 14 measures thepotential at the input terminal to determine the resistance value of thetemperature sensor TM, and determines the temperature of the temperaturesensor TM based on this resistance value. If the temperature sensor TMis arranged on or near the surface of the internal power supply BAT, thetemperature of the temperature sensor TM can be used as the temperatureof the internal power supply BAT.

The controller 14 measures a voltage across a resistor RD connected tothe negative electrode of the internal power supply BAT to determine acurrent flowing through the resistor RD. If this current exceeds athreshold, the controller 14 operates the transistor Q3 or the voltageconverter 13 to stop a current flowing out from the negative electrodeof the internal power supply BAT or a current flowing into the negativeelectrode. Note that by the internal processing of the controller 14,the current flowing out from the negative electrode of the internalpower supply BAT and the current flowing into the negative electrode ofthe internal power supply BAT have positive values. If the currentexceeds the threshold and the current flowing out from the negativeelectrode of the internal power supply BAT or flowing into the negativeelectrode is stopped, the controller 14 can improve the safety of theaerosol generation device 100.

In addition, the controller 14 may stop the current flowing into thenegative electrode of the internal power supply BAT by operating thetransistor Q1 or stop the current flowing into the negative electrode ofthe internal power supply BAT by operating the voltage converter 13 andthe transistor Q1.

The flow of the current during supply of the power supply voltage fromthe external device CG to the power supply unit 102 will be describedbelow with reference to FIG. 3. When the connector 24 of the externaldevice CG is connected to the connector 23 of the power supply unit 102,the external device CG supplies the power supply potential VBUS to oneof the two power supply terminals of the connector 23 of the powersupply unit 102 and supplies the ground potential to the other powersupply terminal. The ground potential is obtained from ground (notshown) provided in the external device CG. The current flowing from thepower supply terminal on the high potential side of the connector 23sets the potential of a node N1 to high level via the polarityunification circuit BC and the protection IC 16. The node N1 is a nodeto which the protection IC 16, the drain of the transistor Q4, and theresistor R4 are connected. When the node N1 is set at high level, acurrent flows through the parasitic diode of the transistor Q4 in theforward direction, so that a node N2 is also set at high level. The nodeN2 is a node to which the source of the transistor Q4, the source of thetransistor Q3, and the cathode of the Schottky diode SD are connected.At this stage, since the transistor Q3 is kept off, the current does notflow over the transistor Q3. In other words, at this stage, the internalpower supply BAT is not charged.

In response to the high level of the potential at the node N1, a currentflows from the node N1 to the ground line GL via the resistor R4 and theresistor R3, so that a node N3 is also set at high level. The node N3 isa node to which the resistor R4, the resistor R3, the enable terminal ofthe switch unit 20, and the detection terminal of the controller 14 areconnected. When the node N3 is set at high level, a high-level signal(the voltage signal) is simultaneously supplied to the enable terminalof the switch unit 20 and the detection terminal of the controller 14.That is, the enable terminal of the switch unit 20 is automatically setat high level when the power supply potential is supplied from theexternal device CG to the power supply terminal of the connector 23.

The node N2 is connected to the power supply terminal of the controller14, the input terminal of the regulator 11, and the power supplyterminal of the LED driver 18, and also to the power supply terminal ofthe LED 19. When the node N2 I set at high level, the operation voltagesare supplied to the controller 14, the LED driver 18, and the LED 19,thereby activating these circuit components. The activated controller 14supplies a high-level signal to the enable terminal of the regulator 11.Accordingly, the regulator 11 supplies the operation voltages to thepower supply terminal of the switch unit 20, the power supply terminalof the puff sensor 21, and the power supply terminal of the touch sensor22.

Upon reception of the operation voltage by the switch unit 20, since thelevel at the enable terminal is high level, the switch unit 20 sets thecommunication path between the connector 23 and the controller 14 to aconductive state. This makes it possible to cause the controller 14 tocommunicate with the external device CG. Since the communication pathbetween the connector 23 and the controller 14 is set at the conductivestate if needed, generation of an abnormality through this communicationpath can be suppressed. In addition, the controller 14 can alsocommunicate with the LED driver 18 and the puff sensor 21.

When the controller 14 sets the transistor Q3 to the ON state, a currentflows from the node N3 to the positive electrode of the internal powersupply BAT. This current charges the internal power supply BAT. Morespecifically, power is supplied from the external device CG to theinternal power supply BAT via a power supply path 301 passing in theorder of the fuse FS, the polarity unification circuit BC, theprotection IC 16, the transistor Q4, and the transistor Q3 from theconnector 23 to the internal power supply BAT. The current flowing outfrom the negative electrode of the internal power supply BAT flows fromthe power supply terminal of the connector 23 on the low potential sideto ground of the external device CG via a power supply path 302. Thepower supply path 302 passes from the negative electrode of the internalpower supply BAT to the connector 23 in the order of the resistor RP,the transistor pair SP, the resistor RD, and the polarity unificationcircuit BC.

In the power supply path 301, the current from the connector 23 issupplied to the source of the transistor Q3, and the current from thedrain of the transistor Q3 is supplied to the positive electrode of theinternal power supply BAT. Accordingly, the controller 14 can controlthe voltage of the gate of the transistor Q3 to supply power from theexternal device CG to the internal power supply BAT. In this manner,since the transistor Q3 is used to control charging of the internalpower supply BAT by a dropper method (this will also be referred to as aseries method or regulator method), the transistor Q3 is also called acharging transistor. The transistor Q3 controlled by the dropper methoddiscards an unnecessary component of the power supplied from theconnector 23 as heat, thereby generating the voltage and current usedfor charging of the internal power supply BAT. The controller 14 may beconfigured to acquire the current and voltage supplied to the transistorQ3. The controller 14 may feed back, to the control of the droppermethod, a difference between the acquired current and voltage and thevoltage and current to be used for charging of the internal power supplyBAT, thereby improving the accuracy of the charging of the internalpower supply BAT. By controlling the charging of the transistor Q3, acharging integrated circuit is unnecessary, thereby reducing the circuitscale.

The controller 14 can acquire the state of the internal power supplyBAT. The state of the internal power supply BAT includes at least one ofthe temperature of the internal power supply BAT and the state of health(SOH) of the internal power supply BAT. The temperature of the internalpower supply BAT and the state of health of the internal power supplyBAT may be determined based on the temperature of the temperature sensorTM or a time required for charging. Alternatively, the temperature ofthe internal power supply BAT and the state of health of the internalpower supply BAT may be acquired by a dedicated IC and acquired by thecontroller 14 by the I2C communication from the dedicated IC. Thecontroller 14 can change at least one of the drain current and theedrain voltage of the transistor Q3 based on the state of the internalpower supply BAT and adjust the power supplied from the external deviceCG to the internal power supply BAT. This makes it possible for thecontroller 14 to control the charging of the internal power supply BATwith a larger degree of freedom.

The parasitic diode of the transistor Q4 is arranged on a path betweenthe polarity unification circuit BC and the positive electrode of theinternal power supply BAT. The forward direction of the parasitic diodeof the transistor Q4 is a direction from the polarity unificationcircuit BC to the positive electrode of the internal power supply BAT.For this reason, the potential (that is, the power supply potentialVBUS) of the node N1 is reduced by the forward voltage of (the parasiticdiode of) the transistor Q4, and the reduced potential is supplied tothe transistor Q3. As described above, the transistor Q3 controlled bythe dropper method discards an unnecessary component of the powersupplied from the connector 23 as heat, thereby generating the voltageand current used for charging of the internal power supply BAT. If powerappropriately reduced by (the parasitic diode of) the transistor Q4 canbe supplied to the transistor Q3, heat generated when the transistor Q3generates the voltage for charging the internal power supply BAT can bereduced. In addition, the heat generated at the time of charging in thepower supply unit 102 can be dispersed to the transistor Q3 and thetransistor Q4. This makes it possible to improve durability of thetransistor Q3 and the power supply unit 102. A diode may be used inplace of the transistor Q4. The forward voltage of the parasitic diodeof the transistor Q4 is higher than the forward voltage of the diode,the potential supplied to the transistor Q3 can be efficiently reducedby using the parasitic diode of the transistor Q4.

The negative electrode of the internal power supply BAT is not connectedto the ground line GL (that is, ground of the power supply unit 102).For this reason, the current from the negative electrode of the internalpower supply BAT flows to ground of the external device CG via theconnector 23. The resistor RP and the resistor RD are connected inseries with each other on the power supply path 302. The current flowingout from the negative electrode of the internal power supply BAT at thetime of charging of the internal power supply BAT passes through theresistor RP and the resistor RD. The protection IC 17 measures a voltageacross the resistor RP and determines the value of the current flowingthrough the resistor RP based on the measured voltage. As in thecontroller 14, the current flowing out from the negative electrode ofthe internal power supply BAT and the current flowing into the negativeelectrode of the internal power supply BAT indicate positive values byprocessing in the protection IC 17. Based on this current value, theprotection IC 17 stops supplying power from the external device CG tothe internal power supply BAT. For example, when this current exceedsthe threshold, the protection IC 17 turns off one or both transistors ofthe transistor pair SP, the current flowing through the power supplypath 302 may be cut off.

The controller 14 measures a voltage across the resistor RD anddetermines the value of the current flowing through the resistor RDbased on the measured voltage. As described above, by the processing inthe controller 14, the current flowing out from the negative electrodeof the internal power supply BAT and the current flowing into thenegative electrode of the internal power supply BAT indicate thepositive values. The controller 14 stops supply of the power from theexternal device CG to the internal power supply BAT based on thiscurrent value. For example, when this current value exceeds thethreshold, the controller 14 may turn off the transistor Q3, therebycutting off the current flowing through the power supply path 301. Inthis manner, when the current flowing through the power supply path 302is monitored by both of the protection IC and the controller 14, thesafety of the power supply unit 102 is further improved. Instead, onlyone of the resistor RP and the resistor RD may be arranged on the powersupply path 302.

When the charging of the internal power supply BAT is complete, thecontroller 14 instructs to stop the supply of the power supply potentialto the external device CG by the I2C communication. At the time ofexcessive discharging of the internal power supply BAT, the controller14 keeps the transistor Q3 off even if the power supply potential issupplied from the external device CG. Note that as a detailed example,the time of excessive discharging of the internal power supply BATindicates the time when the voltage of the internal power supply BAT islower than the discharge end voltage and the voltage for operating thecontroller 14 cannot be supplied to the power supply terminal of thecontroller 14. In other words, at the time of excessive discharging, thecontroller 14 cannot be operated by only the power supplied from theinternal power supply BAT. Even if the transistor Q3 is kept off, theoperation power is supplied from the external device CG to thecontroller 14 via a power supply path 305. The power supply path 305 isa path passing from the connector 23 in the order of the fuse FS, thepolarity unification circuit BC, the protection IC 16, and thetransistor Q4. The power supply path 305 does not pass the transistorQ3. In addition, even if the transistor Q3 is kept off, the operationpower is supplied from the external device CG to the power supplyterminal of the switch unit 20 via a power supply path 304. Morespecifically, since the controller 14 cannot be operated at the time ofexcessive discharging of the internal power supply BAT, the enablesignal is not supplied from the control terminal (“EN1” in FIG. 2) ofthe controller 14 to the enable terminal (“EN” in FIG. 2) of theregulator 11. Accordingly, since the regulator 11 stops the operation,the operation voltage is not supplied to the power supply terminal ofthe switch unit 20. However, if the operation power is supplied from theexternal device CG to the controller 14 via the power supply path 305,the controller 14 can supply the enable signal from the control terminalto the enable terminal of the regulator 11. In addition, the operationpower is also supplied from the external device CG to the input terminalof the regulator 11 via the power supply path 304. Accordingly, theoperation power is supplied from the regulator 11 to the power supplyterminal of the switch unit 20. The power supply path 304 is a pathpassing from the connector 23 in the order of the fuse FS, the polarityunification circuit BC, the protection IC 16, the transistor Q4, and theregulator 11 and does not pass through the transistor Q3. In addition,the high-level signal is supplied to the enable terminal of the switchunit 20. Accordingly, even if the transistor Q3 is kept off, thecontroller 14 can communicate with the external device CG, and forexample, an error state can be transmitted. In addition, even if thetransistor Q3 is kept off, since the power is supplied from theregulator 11 to the LED driver 18, the controller 14 uses the LED 19 tonotify the user of the error.

If the transmitted error state is minor, while the controller 14 isoperating with the operation power supplied from the external device CG,the controller 14 controls the transistor Q3 to restore the internalpower supply BAT from the excessive discharging state. Even in thisstate, the controller 14 can control the transistor Q3 in accordancewith the dropper method. Note that before at least the voltage of theinternal power supply BAT is equal to or higher than the discharge endvoltage, the controller 14 may control the transistor Q3 so that thevoltage and current supplied to the internal power supply BAT are lowerand smaller than those in the normal operation. Note that as a detailedexample, the normal operation indicates the time when the voltage of theinternal power supply BAT is equal to or higher than the discharge endvoltage.

The flow of a current when the power supply potential is not suppliedfrom the external device CG to the power supply unit 102 will bedescribed with reference to FIG. 4. When the controller 14 instructs tocause the external device CG not to supply the power supply potential orthe external device CG is not connected to the power supply unit 102,the power supply potential is not supplied from the external device CGto the power supply unit 102.

The current flowing out from the positive electrode of the internalpower supply BAT is supplied to the power supply terminal of thecontroller 14 via the power supply path 403 passing in the order of anode N4, the Schottky diode SD, and the node N2. By this current, thecontroller 14 receives the operation power. Since the forward resistanceof the Schottky diode SD is lower than the forward resistance of thetransistor Q3, the current mainly flows in the Schottky diode SD fromthe node N4 to the node N2. By arranging the Schottky diode SD in thismanner, the power can be supplied to the controller 14 with a higherefficiency (that is, a low loss) than a case in which the current flowsto the parasitic diode of the transistor Q3.

The node N2 is also connected to the input terminal of the regulator 11,the power supply terminal of the LED driver 18, and the power supplyterminal of the LED 19. When the node N2 is set at high level, theoperation power is supplied to each of the LED driver 18 and the LED 19.The controller 14 supplies the high-level signal to the enable terminalof the regulator 11. Accordingly, the regulator 11 supplies theoperation power to each of the power supply terminal of the switch unit20, the power supply terminal of the puff sensor 21, and the powersupply terminal of the touch sensor 22.

The parasitic diode of the transistor Q4 is arranged on a path betweenthe node N2 and the connector 23. The reverse direction of the parasiticdiode of the transistor Q4 is a direction from the node N2 to theconnector 23. For this reason, no current flows from the node N2 to theconnector 23. In this manner, the parasitic diode of the transistor Q4functions as a reverse flow prevention element. That is, the transistorQ4 serves as the reverse flow prevention element and also serves as anelement for suppressing heating of the transistor Q3 at the time ofcharging. The transistor Q4 is an element for suppressing theconcentration of heat in the power supply unit 102 at the time ofcharging. Since the current does not flow from the node N2 to the nodeN1, when the power supply potential is not supplied from the externaldevice CG to the power supply unit 102, the potential of the node N1 isset at low level, and accordingly the low-level signal is supplied tothe enable terminal of the switch unit 20. For this reason, the switchunit 20 sets the communication path between the connector 23 and thecontroller 14 to the disconnected state. As a result, the communicationterminal of the connector 23 is set in a state in which thecommunication terminal of the controller 14 is disconnected from thecommunication terminal of another circuit component (for example, thepuff sensor 21). For this reason, even if static electricity is appliedto the communication terminal of the connector 23 or the communicationterminal is short-circuited, no unexpected current flows in the circuitcomponents in the power supply unit 102. Therefore, the safety of thepower supply unit 102 can be improved.

Even if the communication path between the connector 23 and thecontroller 14 is set in the disconnected state, the controller 14 cancommunicate with another circuit component (for example the puff sensor21) in the power supply unit 102. That is, in both a case in which thecommunication path between the connector 23 and the controller 14 is setin the conductive state and a case in which this communication path isset in the disconnected state, the communication terminal of thecontroller 14 and the communication path of another integrated circuit(for example, the puff sensor 21) are set in the conductive state. Notethat another switch unit may be arranged in the communication pathbetween the controller 14 and the other integrated circuit, and thestate may be switched independently of the communication path betweenthe connector 23 and the controller 14.

When heating the heater HT, the controller 14 turns on the transistorQ1. Accordingly, a current flows from the positive electrode of theinternal power supply BAT to the heater HT via a power supply path 401.The power supply path 401 is a path from the positive electrode of theinternal power supply BAT to the electrical contact C1 via the voltageconverter 13. The power supply path 401 does not pass through thetransistor Q3. Accordingly, since a decrease in power supplied from theinternal power supply BAT to the heater HT can be suppressed,high-efficiency aerosol generation is possible. In particular, if thevoltage converter 13 is formed by a boost DC/DC converter or abuck-boost DC/DC converter, a higher voltage can be supplied to theheater HT. The amount of aerosol to be generated can be increased.

The current passing through the heater HT flows into the negativeelectrode of the internal power supply BAT via the power supply path402. The power supply path 402 is a path from the electrical contact C2to the negative electrode of the internal power supply BAT via theresistor RD, the transistor pair SP, and the resistor RP. Since thenegative electrode of the internal power supply BAT is not connected tothe ground line GL, the current passing through the heater HT passesthrough the resistor RD and the resistor RP as described above.

The protection IC 17 measures a voltage across the resistor RP todetermine the value of a current flowing through the resistor RP basedon the measured voltage. The protection IC 17 stops the supply of thepower from the internal power supply BAT to the heater HT based on thiscurrent value. For example, if this current value exceeds the threshold,the protection IC 17 turns off both the transistors of the transistorpair SP, and the current flowing through the power supply path 402 canbe cut off.

The controller 14 measures a voltage across the resistor RD to determinethe value of a current flowing through the resistor RD based on themeasured voltage. The controller 14 stops the supply of power from theinternal power supply BAT to the heater HT based on this current value.For example, if this current value exceeds the threshold, the controller14 turns off the transistor Q1 and/or stops supplying the enable signalfrom the control terminal (“EN2” in FIG. 2) to the enable terminal (“EN”in FIG. 2) of the voltage converter 13, the controller 14 cuts off thecurrent flowing through the power supply path 401. In this manner, whenthe current flowing through the power supply path 302 is monitored byboth the protection IC and the controller 14, the safety of the powersupply unit 102 can be further improved. Instead, only one of theresistor RP and the resistor RD may be arranged on the power supply path402.

In the above embodiment, the resistor RP and the resistor RD arearranged in the common portion between the power supply path 302 and thepower supply path 402. Instead, at least one of the resistor RP and theresistor RD may be arranged to pass through only one of the power supplypath 302 and the power supply path 402. In addition, the power supplyunit 102 need not monitor the current passing through the resistor RPand the resistor RD. In addition, the resistor RP or the resistor RD maybe arranged in the power supply path 401. On the other hand, as in theembodiment shown in FIG. 2, if the resistor RP and the resistor RD arearranged in the common portion between the power supply path 302 and thepower supply path 402, the common mode voltage of the operationalamplifier can be set low or zero. If the common mode voltage is low, awide variety of choices can be set for the differential amplifier, whichis advantageous from the viewpoint of cost. In this embodiment, each ofthe protection IC 17 and the controller 14 may include an operationalamplifier for acquiring the voltage applied to the resistor RP and theresistor RD.

In the above embodiment, the transistor Q4 may be located at anotherposition. For example, the transistor Q4 may be arranged between thepolarity unification circuit BC and the protection IC 16. In addition,the protection IC 16 may be located at another position. For example,the protection IC 16 may be arranged between the node N1 and thetransistor Q4.

The polarity unification circuit BC and the connector 23 will bedescribed in detail with reference to FIGS. 5A and 5B. Some circuitcomponents in FIG. 2 are not illustrated in FIGS. 5A and 5B. Theconnector 23 of the power supply unit 102 can be connected to theexternal device CG (more specifically, its connector 24). The connector23 includes a write terminal 501, two power supply terminals 502 and503, and four communication terminals 504 to 507. The write terminal 501is a terminal used to cause the external device CG to write data in thecontroller 14 of the power supply unit 102. The power supply terminals502 and 503 are terminals used to cause the power supply unit 102 toreceive supply of the power from the external device CG. Thecommunication terminals 504 to 507 are terminals used to cause thecontroller 14 of the power supply unit 102 to communicate with theexternal device CG. As described above, in some embodiments,communication between the power supply unit 102 and the external deviceCG is performed by the I2C communication. The communication terminals504 and 505 are used to communicate the clock signal in the I2Ccommunication. The communication terminals 506 and 507 are used tocommunicate the data signal in the I2C communication.

The write terminal 501 of the connector 23 is connected to a writeterminal 553 of the controller 14. Both the power supply terminals 502and 503 of the connector 23 are connected to the polarity unificationcircuit BC. The communication terminals 504 and 505 of the connector 23are connected to a terminal 541 of the switch unit 20. Both thecommunication terminals 506 and 507 of the connector 24 are connected toa terminal 542 of the switch unit 20.

A terminal 543 of the switch unit 20 is connected to the communicationterminal 551 of the controller 14. A terminal 544 of the switch unit 20is connected to the communication terminal 552 of the controller 14. Theswitch unit 20 includes a switch 546 connected between the terminal 541and the terminal 543 and a switch 547 connected between the terminal 542and the terminal 544. When the switch 546 is set ON, the path betweenthe terminal 541 and the terminal 543 is set in the conductive state.When the switch 546 is set OFF, the path between the terminal 541 andthe terminal 543 is set in the disconnected state. When the switch 547is set ON, the path between the terminal 542 and the terminal 544 is setin the conductive state. When the switch 547 is set OFF, the pathbetween the terminal 542 and the terminal 544 is set in the disconnectedstate. When a high-level signal is input to the enable terminal EN, theswitch unit 20 turns on the switches 546 and 547. When a low-levelsignal is input to the enable terminal EN, the switch unit 20 turns offthe switches 546 and 547.

A communication path 571 for communicating the clock signal is formedbetween the communication terminal 504 of the connector 23 and acommunication terminal 551 of the controller 14. Since the switch 546 ispositioned on this communication path 571, if the switch 546 is turnedon, the communication path 571 is set in the conductive state. If theswitch 546 is turned off, the communication path 571 is set in thedisconnected state. Of the communication path 571, the communicationterminal 505 of the connector 23 is connected to a node 536 between thecommunication terminal 504 of the connector 23 and the switch 546.Therefore, the clock signal transmitted from the communication terminal551 of the controller 14 is output from both the communication terminal504 and the communication terminal 505 of the connector 23.

A communication path 572 for communicating the data signal is formedbetween the communication terminal 506 of the connector 23 and acommunication terminal 552 of the controller 14. Since the switch 547 ispositioned on this communication path 572, if the switch 547 is turnedon, the communication path 572 is set in the conductive state. If theswitch 547 is turned off, the communication path 572 is set in thedisconnected state. Of the communication path 572, the communicationterminal 507 of the connector 23 is connected to a node 535 between thecommunication terminal 506 of the connector 23 and the switch 547.Therefore, the data signal transmitted from the communication terminal552 of the controller 14 is output from both the communication terminal506 and the communication terminal 507 of the connector 23.

The connector 24 of the external device CG includes a write terminal511, two power supply terminals 512 and 513, and four communicationterminals 514 to 517. The write terminal 511 is a terminal used to causethe external device CG to write data in the controller 14 of the powersupply unit 102. The write terminal 511 is connected to a write terminal583 of a controller 580 of the external device CG. The power supplyterminals 512 and 513 are terminals used to cause the external device CGto supply power to the power supply unit 102. The external device CG(more specifically, its voltage generation circuit 590) supplies thepower supply potential to the power supply terminal 512. The powersupply terminal 513 is connected to ground of the external device CG.The communication terminals 514 to 517 are terminals used to cause theexternal device CG to communicate with the controller 14 of the powersupply unit 102. The communication terminals 514 and 515 are used tocommunicate the clock signal in the I2C communication. The communicationterminals 516 and 517 are used to communicate the data signal in the I2Ccommunication. Both the communication terminals 514 and 515 of theconnector 24 are connected to a communication terminal 581 of thecontroller 580 of the external device CG. Both the communicationterminals 516 and 517 of the connector 24 are connected to acommunication terminal 582 of the controller 580 of the external deviceCG.

The connector 23 and the connector 24 can be connected in two differentdirections. More specifically, the connector 23 and the connector 24 areconnectable in a direction indicated in FIG. 5A and a directionindicated in FIG. 5B. The direction of the connector 24 in FIG. 5B is adirection 180° rotated from the direction of the connector 24 in FIG.5A.

If the connector 23 is connected to the connector 24 in the directionindicated in FIG. 5A, the respective terminals of the two connectors areconnected indicated by broken lines in FIG. 5A. More specifically, thewrite terminal 501 is connected to the write terminal 511, the powersupply terminal 502 is connected to the power supply terminal 512, thepower supply terminal 503 is connected to the power supply terminal 513,the communication terminal 504 is connected to the communicationterminal 514, the communication terminal 505 is connected to thecommunication terminal 515, the communication terminal 506 is connectedto the communication terminal 516, and the communication terminal 507 isconnected to the communication terminal 517. In this case, the powersupply potential is supplied to the power supply terminal 502 of theconnector 23, and the ground potential is supplied to the power supplyterminal 503 of the connector 23.

When the connector 23 is connected to the connector 24 in the directionindicated in FIG. 5B, the respective terminals of the two connectors areconnected as indicated by the broken lines in FIG. 5B. Morespecifically, the write terminal 501 is connected to the write terminal511, the power supply terminal 502 is connected to the power supplyterminal 513, the power supply terminal 503 is connected to the powersupply terminal 512, the communication terminal 504 is connected to thecommunication terminal 515, the communication terminal 505 is connectedto the communication terminal 514, the communication terminal 506 isconnected to the communication terminal 517, and the communicationterminal 507 is connected to the communication terminal 516. In thiscase, the power supply potential is supplied to the power supplyterminal 503 of the connector 23, and the ground potential is suppliedto the power supply terminal 502 of the connector 23.

Since the write terminal 501 is positioned at the center of theconnector 23 and the write terminal 511 is positioned at the center ofthe connector 24, the write terminal 501 and the write terminal 511 areconnected regardless of the direction of connecting the connector 23 andthe connector 24. For this reason, the data output from the writeterminal 511 of the controller 580 of the external device CG is writtenin the write terminal 553 of the controller 14 of the power supply unit102 regardless of the direction of connecting the connector 23 and theconnector 24. As described above, when the terminals are located at thecenters of the connectors 23 and 24, the number of terminals required toallow connection in the plurality of directions can be reduced.

All the communication terminals 504 and 505 of the connector 23 and thecommunication terminals 514 and 515 of the connector 24 are used forcommunicating the clock signal. Regardless of the direction ofconnecting the connector 23 and the connector 24, the clock signal iscommunicated between the communication terminal 581 of the controller580 of the external device CG and the communication terminal 551 of thecontroller 14 of the power supply unit 102. All the communicationterminals 506 and 507 of the connector 23 and the communicationterminals 516 and 517 of the connector 24 are used for communicating thedata signal. Regardless of the direction of connecting the connector 23and the connector 24, the data signal is communicated between thecommunication terminal 582 of the controller 580 of the external deviceCG and the communication terminal 552 of the controller 14 of the powersupply unit 102.

In this embodiment, each of the connector 23 and the connector 24includes two communication terminals used to communicate the clocksignal and two communication terminals used to communicate the datasignal. Instead, one of the connector 23 and the connector 24 mayinclude one communication terminal used to communicate the clock signaland/or one communication terminal used to communicate the data signal.

If the connector 23 includes only the communication terminal 504 as thecommunication terminal used to communicate the clock signal, thecommunication terminal 504 is connected to the communication terminal514 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 504 is connected to the communication terminal 515. If theconnector 23 includes only the communication terminal 505 as thecommunication terminal used to communicate the clock signal, thecommunication terminal 505 is connected to the communication terminal515 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 505 is connected to the communication terminal 514. If theconnector 23 includes only the communication terminal 506 as thecommunication terminal used to communicate the data signal, thecommunication terminal 506 is connected to the communication terminal516 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 506 is connected to the communication terminal 517. If theconnector 23 includes only the communication terminal 507 as thecommunication terminal used to communicate the data signal, thecommunication terminal 506 is connected to the communication terminal517 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 507 is connected to the communication terminal 516. Even if theconnector 23 includes one communication terminal used to communicate theclock signal and/or the communication terminal used to communicate thedata signal, and if the connector 24 includes two communicationterminals used to communicate the clock signal and/or two communicationterminals used to communicate the data signal, the communication ispossible between the controller 580 of the external device CG and thecontroller 14 of the power supply unit 102 regardless of the directionof connecting the connector 23 and the connector 24.

If the connector 24 includes only the communication terminal 514 as thecommunication terminal used to communicate the clock signal, thecommunication terminal 514 is connected to the communication terminal504 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 514 is connected to the communication terminal 505. If theconnector 23 includes only the communication terminal 515 as thecommunication terminal used to communicate the clock signal, thecommunication terminal 515 is connected to the communication terminal505 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 515 is connected to the communication terminal 504. If theconnector 23 includes only the communication terminal 516 as thecommunication terminal used to communicate the data signal, thecommunication terminal 516 is connected to the communication terminal506 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 516 is connected to the communication terminal 507. If theconnector 23 includes only the communication terminal 517 as thecommunication terminal used to communicate the data signal, thecommunication terminal 517 is connected to the communication terminal507 if the connector 23 and the connector 24 are connected in thedirection indicated in FIG. 5A. If the connector 23 is connected to theconnector 24 in the direction indicated in FIG. 5B, the communicationterminal 517 is connected to the communication terminal 506. Even if theconnector 24 includes one communication terminal used to communicate theclock signal and/or the communication terminal used to communicate thedata signal, and if the connector 23 includes two communicationterminals used to communicate the clock signal and/or two communicationterminals used to communicate the data signal, the communication ispossible between the controller 580 of the external device CG and thecontroller 14 of the power supply unit 102 regardless of the directionof connecting the connector 23 and the connector 24.

The polarity unification circuit BC includes four diodes 521 to 524 andfour nodes 531 to 534. The node 531 is connected to the cathode of thediode 521 and the cathode of the diode 522. The node 534 is connected tothe anode of the diode 523 and the anode of the diode 524. The node 532is connected to the power supply terminal 502 of the connector 23, theanode of the diode 521, and the cathode of the diode 523. The node 533is connected to the power supply terminal 503 of the connector 23, theanode of the diode 522, and the cathode of the diode 524.

When the connector 23 is connected to the connector 24 in the directionindicated in FIG. 5A, a current flows from the power supply terminal 512of the connector 24 of the external device CG to a positive electrode561 of the internal power supply BAT via the diode 521 and the node 531(that is, in the power supply path 301), and a current flows from anegative electrode 562 of the internal power supply BAT to the powersupply terminal 513 of the connector 24 of the external device CG viathe node 534 and the diode 524 (that is, in the power supply path 302).When the connector 23 is connected to the connector 24 in the directionindicated in FIG. 5B, a current flows from the power supply terminal 512of the connector 24 of the external device CG to the positive electrode561 of the internal power supply BAT via the diode 522 and the node 531(that is, in the power supply path 301), and a current flows from thenegative electrode 562 of the internal power supply BAT to the powersupply terminal 513 of the connector 24 of the external device CG viathe node 534 and the diode 523 (that is, in the power supply path 302).As described above, regardless of the direction of connecting theconnector 23 to the connector 24, the power can be supplied from theexternal device CG to the internal power supply BAT. Note that if partof the power supply path 302 is set at the same potential as the groundpotential of the external device CG, the current flowing out from thepower supply terminal 512 of the connector 24 does not flow into groundof the external device CG, but flows in part of the power supply path302 which is set at the same potential as the ground potential of theexternal device CG. This also applies to the flow of the current shownin FIG. 3.

In this embodiment, the power supply unit 102 includes the fuse FSarranged on the path between the node 532 and the power supply terminal502. For this reason, when an excessive current flows in the powersupply path 301 (in the case of FIG. 5A) or the power supply path 302(in the case of FIG. 5B), the fuse FS is disconnected, and the powersupply is stopped. Accordingly, the safety of the power supply unit 102can be improved. A fuse may be arranged on the path between the node 533and the power supply terminal 503 in addition to or in place of the fuseFS arranged on the path between the node 532 and the power supplyterminal 502. If the fuses are arranged on the path between the node 532and the power supply terminal 502 and the path between the node 533 andthe power supply terminal 503, the safety of the power supply unit 102can be further improved. On the other hand, if the fuse is arranged onone of the path between the node 532 and the power supply terminal 502and the path between the node 533 and the power supply terminal 503, thesafety of the power supply unit 102 can be improved, and at the sametime the cost can be reduced. In this embodiment, the fuse FS isarranged on the path between the node 532 and the power supply terminal502. In place of this, the fuse FS may be arranged at any position ofthe power supply path 301 and the power supply path 302. Regardless ofthe position of the fuse, an excessive current can be suppressed.

As described above, whether the current supplied from the power supplyterminal 512 of the connector 24 passes through the path connecting thepower supply terminal 502 and the node 532 or the path connecting thepower supply terminal 503 and the node 533 is determined depending onthe direction of connecting the connector 23 and the connector 24. Thatis, when the connector 23 is connected to the connector 24 in thedirection indicated in FIG. 5A, a current supplied from the power supplyterminal 512 of the connector 24 flows through a path connecting thepower supply terminal 502 and the node 532. when the connector 23 isconnected to the connector 24 in the direction indicated in FIG. 5B, acurrent supplied from the power supply terminal 512 of the connector 24flows through a path connecting the power supply terminal 503 and thenode 533. When the connector 23 is connected to the connector 24 in thedirection indicated in FIG. 5A and the fuse FS is arranged on the pathconnecting the power supply terminal 502 and the node 532, anotherelement present on the power supply path 301 and the power supply path302 can be appropriately protected from the excessive current. However,when the connector 23 is connected to the connector 24 in the directionindicated in FIG. 5B and the fuse FS is arranged on the path connectingthe power supply terminal 503 and the node 533, the current flows to theother element present on the power supply path 301 and the power supplypath 302 until the fuse FS is disconnected. When the connector 23 isconnected to the connector 24 in the direction indicated in FIG. 5A andthe fuse FS is arranged on only the path connecting the power supplyterminal 503 and the node 533, the same phenomenon described aboveoccurs. If the fuses FZ are arranged on the path connecting the powersupply terminal 502 and the node 532 and the path connecting the powersupply terminal 503 and the node 533, this phenomenon can be prevented.However, if the plurality of fuses are provided, the volume of the powersupply unit 102 may increase.

Instead of using the plurality of fuses, if the protection IC 16 isarranged between the polarity unification circuit BC and the node N2 asshown in FIG. 2, an element connected to the output side of theprotection IC 16 can be protected regardless of the direction ofconnecting the connector 23 and the connector 24. If the protection IC16 and the fuse FS are provided, and even if any trouble occurs in theprotection IC 16, an excessive current can be suppressed. In addition,if the transistor Q4 is located downstream of the protection IC 16 whenviewed from the flow of the current supplied from the polarityunification circuit BC, power supply from the internal power supply BATto the protection IC 16 can be suppressed. Therefore, the operation orfailure of the protection IC 16 can be suppressed.

Among protection elements including the fuse FS, the protection IC 16,and the transistor Q4, the fuse FS may be arranged between the connector23 and the polarity unification circuit BC, and the protection IC 16 andthe transistor Q4 may be arranged between the polarity unificationcircuit BC and the node N2. In addition, when viewed from the flow ofthe current supplied from the polarity unification circuit BC, thetransistor Q4 may be located downstream of the protection IC 16.

As has been described above, the power supply unit 102 has theabove-described arrangement of the connector 23 and the above-describedarrangement of the polarity unification circuit BC. Accordingly, theconnector 23 of the power supply unit 102 can be connected in any one ofthe two directions of the connector 24 of the external device CG,thereby improving convenience of the user.

Summary of Embodiments

-   Item 1. A power supply unit (102) for an aerosol generation device    (100), the power supply unit (102) comprising:

an internal power supply (BAT) configured to hold power supplied to aheater (HT) configured to heat an aerosol source;

a connector (23) connectable to an external power supply (CG);

a controller (14) configured to control power supply from the internalpower supply (BAT) to the heater (HT); and

a first transistor (Q3) positioned on a first power supply path (301)between the connector (23) and a positive electrode (561) of theinternal power supply (BAT),

wherein a current from the connector (23) is supplied to a source of thefirst transistor (Q3), and a current from a drain of the firsttransistor (Q3) is supplied to the positive electrode (561) of theinternal power supply (BAT), and

the controller (14) controls a voltage of a gate of the first transistor(Q3) to adjust power supplied from the external power supply (CG) to theinternal power supply (BAT).

-   Item 2. The power supply unit (102) according to Item 1, further    comprising a second power supply path (401) configured to supply    power from the positive electrode (561) of the internal power supply    (BAT) to the heater (HT) without being through the first transistor    (Q3).-   Item 3. The power supply unit (102) according to Item 1 or 2,    wherein

the controller (14) can acquire a state of the internal power supply(BAT), and

the controller (14) changes at least one of a drain current and a drainvoltage of the first transistor (Q3) based on the state of the internalpower supply (BAT), thereby adjusting the power supplied from theexternal power supply (CG) to the internal power supply (BAT).

-   Item 4. The power supply unit (102) according to Item 3, wherein the    state of the internal power supply (BAT) includes at least one of a    temperature of the internal power supply (BAT) and a degraded state    of the internal power supply (BAT).-   Item 5. The power supply unit (102) according to any one of Items 1    to 4, further comprising:

a circuit board mounted with the controller (14) and including ground;and

a current detection circuit (14, 17) configured to detect at least oneof a first current flowing from a negative electrode (562) of theinternal power supply (BAT) at the time of charging the internal powersupply (BAT) and a second current flowing into the negative electrode(562) of the internal power supply (BAT) at the time of discharging fromthe internal power supply (BAT),

wherein the negative electrode (562) of the internal power supply (BAT)is not connected to the ground of the power supply unit (102).

-   Item 6. The power supply unit (102) according to Item 5, further    comprising:

a first resistor (RP) and a second resistor (RD) through which at leastone of the first current and the second current flows; and

a protection integrated circuit (17) configured to measure a voltageacross the first resistor (RP),

wherein the protection integrated circuit (17) determines a value of acurrent flowing through the first resistor (RP) based on the voltageacross the first resistor (RP), and

the controller (14) measures a voltage across the second resistor (RD)and determines a value of a current flowing through the second resistor(RD) based on the voltage across the second resistor (RD).

-   Item 7. The power supply unit (102) according to Item 6, wherein

the connector (23) includes a first power supply terminal (502, 503)configured to receive a ground potential from the external power supply(CG), and

the first resistor (RP) and the second resistor (RD) are positioned on apath between the negative electrode (562) of the internal power supply(BAT) and the first power supply terminal (502, 503) of the connector(23).

-   Item 8. The power supply unit (102) according to any one of Items 1    to 7, wherein the source of the first transistor (Q3) is further    connected to a power supply terminal of the controller (14).-   Item 9. The power supply unit (102) according to any one of Items 1    to 8, further comprising:

a notification unit (18, 19) configured to notify a user of the state ofthe power supply unit (102); and

a regulator (11) configured to supply operation power to thenotification (18, 19) unit,

wherein the source of the first transistor (Q3) is further connected toa power supply terminal of the regulator (11).

-   Item 10. The power supply unit (102) according to Item 9, wherein    the source of the first transistor (Q3) is further connected to the    power supply terminal of the controller (14).-   Item 11. The power supply unit (102) according to any one of Items 1    to 10, further comprising a Schottky diode (SD),

wherein an anode of the Schottky diode (SD) is connected to the drain ofthe first transistor (Q3), and a cathode of the Schottky diode (SD) isconnected to the source of the first transistor (Q3).

-   Item 12. The power supply unit (102) according to any one of Items 1    to 11, further comprising a reverse flow prevention element arranged    on a path between the first transistor (Q3) and the connector (23),    a reverse direction of the reverse flow prevention element being a    direction from the first transistor (Q3) to the connector (23).-   Item 13. The power supply unit (102) according to Item 12, further    comprising a second transistor (Q4) arranged on a path between the    first transistor (Q3) and the connector (23),

wherein the reverse flow prevention element is a parasitic diode of thesecond transistor (Q4).

The invention is not limited to the foregoing embodiments, and variousvariations/changes are possible within the spirit of the invention.

What is claimed is:
 1. A power supply unit for an aerosol generationdevice, the power supply unit comprising: an internal power supplyconfigured to hold power supplied to a heater configured to heat anaerosol source; a connector connectable to an external power supply; acontroller configured to control power supply from the internal powersupply to the heater; a first transistor of a dropper type positioned ona first power supply path between the connector and a positive electrodeof the internal power supply; a circuit board mounted with thecontroller and including ground; and a current detection circuitconfigured to detect at least one of a first current flowing from anegative electrode of the internal power supply at the time of chargingthe internal power supply and a second current flowing into the negativeelectrode of the internal power supply at the time of discharging fromthe internal power supply, wherein a current from the connector issupplied to a source of the first transistor, and a current from a drainof the first transistor is supplied to the positive electrode of theinternal power supply, the controller performs feedback control on avoltage of a gate of the first transistor based on a current or avoltage supplied from the first transistor, thereby adjusting powersupplied from the external power supply to the internal power supply,and wherein the negative electrode of the internal power supply is notconnected to the ground of the power supply unit.
 2. The power supplyunit according to claim 1, further comprising a second power supply pathconfigured to supply power from the positive electrode of the internalpower supply to the heater without being through the first transistor.3. The power supply unit according to claim 1, wherein the controllercan acquire a state of the internal power supply, and the controllerchanges at least one of a drain current and a drain voltage of the firsttransistor based on the state of the internal power supply, therebyadjusting the power supplied from the external power supply to theinternal power supply.
 4. The power supply unit according to claim 3,wherein the state of the internal power supply includes at least one ofa temperature of the internal power supply and a degraded state of theinternal power supply.
 5. The power supply unit according to claim 1,further comprising: a first resistor and a second resistor through whichat least one of the first current and the second current flows; and aprotection integrated circuit configured to measure a voltage across thefirst resistor, wherein the protection integrated circuit determines avalue of a current flowing through the first resistor based on thevoltage across the first resistor, and the controller measures a voltageacross the second resistor and determines a value of a current flowingthrough the second resistor based on the voltage across the secondresistor.
 6. The power supply unit according to claim 5, wherein theconnector includes a first power supply terminal configured to receive aground potential from the external power supply, and the first resistorand the second resistor are positioned on a path between the negativeelectrode of the internal power supply and the first power supplyterminal of the connector.
 7. The power supply unit according to claim1, wherein the source of the first transistor is further connected to apower supply terminal of the controller.
 8. The power supply unitaccording to claim 1, further comprising: a notification unit configuredto notify a user of the state of the power supply unit; and a regulatorconfigured to supply operation power to the notification unit, whereinthe source of the first transistor is further connected to a powersupply terminal of the regulator.
 9. The power supply unit according toclaim 8, wherein the source of the first transistor is further connectedto the power supply terminal of the controller.
 10. The power supplyunit according to claim 1, further comprising a reverse flow preventionelement arranged on a path between the first transistor and theconnector, a reverse direction of the reverse flow prevention elementbeing a direction from the first transistor to the connector.
 11. Thepower supply unit according to claim 10, further comprising a secondtransistor arranged on a path between the first transistor and theconnector, wherein the reverse flow prevention element is a parasiticdiode of the second transistor.
 12. A power supply unit for an aerosolgeneration device, the power supply unit comprising: an internal powersupply configured to hold power supplied to a heater configured to heatan aerosol source; a connector connectable to an external power supply;a controller configured to control power supply from the internal powersupply to the heater; a first transistor of a dropper type positioned ona first power supply path between the connector and a positive electrodeof the internal power supply; and a Schottky diode, wherein a currentfrom the connector is supplied to a source of the first transistor, anda current from a drain of the first transistor is supplied to thepositive electrode of the internal power supply, and the controllerperforms feedback control on a voltage of a gate of the first transistorbased on a current or a voltage supplied from the first transistor,thereby adjusting power supplied from the external power supply to theinternal power supply, and an anode of the Schottky diode is connectedto the drain of the first transistor, and a cathode of the Schottkydiode is connected to the source of the first transistor.